A Chemical Mechanical Polishing (CMP) technique may be a technique for planarizing a surface of a predetermined film, that is, an object to be polished, formed on a silicon substrate used when manufacturing an ultrahigh integrated semiconductor. In a CMP process, a slurry including abrasive particles such as silica, alumina, ceria, and the like, a deionized water, a pH stabilizer, a surfactant, and the like may be used. As most important factors in the CMP process, a polishing speed, quality of a polishing surface, that is, an occurrence rate of micro-scratch on the polishing surface may be given. These two factors may rely greatly on a degree of dispersion of the abrasive particles, characteristics of the polishing surface, crystallinity of the abrasive particles, and the like.
When a size of the abrasive particles or a degree of crystallinity of the abrasive particles increases, the polishing speed increases, however, at the same time the occurrence rate of micro scratch on the polishing surface disadvantageously increases. Accordingly, in order to minimize the occurrence rate of micro scratch after polishing, the size of the abrasive particles and crystallinity of the abrasive particles may need to be optimized.
In addition, a ceria slurry using ceria as the abrasive particles may be widely used in comparison with other slurries due to its high etching selectivity of an oxide film with respect to a nitride film. The ceria included in the ceria slurry may be manufactured by a solid-phase synthesis method in which a raw material precursor is directly calcined and oxidized in the atmosphere. However, the ceria manufactured by the solid-phase synthesis method may have a high crystallinity and hardness, and thus occurrence of the micro scratch may be increased.